Radiotherapy has been used in the treatment of cancer and some non cancerous conditions for more than 100 years. It is the use of high-energy ionising radiation such as x-rays, gamma rays, electrons, neutrons, protons and other sources to cure or relieve symptoms of cancer and reduce the chance of cancer returning after surgery.
Technological advances in tumour visualisation and radiotherapy treatment delivery have, and continue to, reduce the side effects of radiotherapy treatments.
Radiotherapy can be given externally from outside of the body or internally from within the body. External radiotherapy can be administered by several different types of radiotherapy machines that work in different ways. For most cancers, radiotherapy is given as an outpatient from Monday to Friday, with a rest at the weekend using machines called linear accelerators (LinAcs).
Internal radiotherapy can be administered by placing solid radioactive material (the source) close to or inside the tumour for a limited period of time (brachytherapy).
Internal radiotherapy can also be administered by using a radioactive liquid, which is given either as a drink or as an injection into a vein (nuclear medicine). A stay in hospital may be required so that special precautions can be taken whilst the radioactive material is in place in your body. Once the treatment is over and the radioactive material is removed there is no risk to friends and family.
Half of all cancer patients will have some form of radiotherapy included in their treatment management. Radiotherapy contributes to 40% of all cured cancers. The use of radiotherapy depends on a range of factors including the tumour type, location and stage as well as the overall health of the patient. Radiotherapy can be used in combination with other treatments such as surgery, chemotherapy and hormone therapy. Radical radiotherapy is used when the aim of treatment is to cure a cancer. The treatment is delivered in small daily doses (fractions) over a two to seven week period damaging the cancer cells irreparably but allowing the normal healthy cells to recover. Palliative radiotherapy is used when the aim is to relieve the symptoms of a cancer. Treatment doses are lower and delivered over a shorter period of time, sometimes a single dose. Neoadjuvant treatment is where radiotherapy is used prior to surgery to shrink the cancer making the surgery easier. Adjuvant treatment is where radiotherapy is given after surgery to ensure no cancer cells are left behind.
Radiotherapy works by depositing energy within the cells of the treated area. This causes damage to the cells DNA. This damage is irreparable in cancer cells and renders them incapable of replication. Normal cells can also be damaged but are usually able to repair themselves. Different tumour types respond to radiotherapy in different ways, some being more or less sensitive, which is why a range of doses and schedules are used.